Automatic doors and revolving doors may become dangerous to users if their danger zones in front of the door leaf are not monitored. Since the dangerous components move during the opening and closing process, the danger area to be monitored also concomitantly moves. Furthermore, the size of the area to be monitored must possibly change during movement. This results in the need to concomitantly move the monitoring sensor with the dangerous component, in which case adaptation to the wide variety of different door sizes and required monitoring areas is desirable. Economic factors also require the provision of a universal sensor with monitoring properties which can be easily adapted.
On account of the given requirements, the industry is looking for sensor solutions with flexible evaluation possibilities which evaluate, for example, the third dimension which relates to the distance between the object being monitored and the sensor. Such sensors can also be used for static mounting for monitoring applications for particular monitoring areas.
The prior art discloses active infrared sensors which are mounted on a door leaf and monitor the area in front of the plane of the door at a few points. As an alternative to this, laser sensors which scan the monitoring area using beams moved using rotation mechanisms are known. However, such sensors are very complex and are therefore associated with considerable production costs. In addition, these sensors provide considerably restricted convenience during installation and adaptation to the monitoring area since a multiplicity of optical components have to be aligned.